From: Masashi Honma masashi.honma@gmail.com
commit 4b2c5a14cd8005a900075f7dfec87473c6ee66fb upstream.
commit 1222a1601488 ("nl80211: Fix possible Spectre-v1 for CQM RSSI thresholds") was incomplete and requires one more fix to prevent accessing to rssi_thresholds[n] because user can control rssi_thresholds[i] values to make i reach to n. For example, rssi_thresholds = {-400, -300, -200, -100} when last is -34.
Cc: stable@vger.kernel.org Fixes: 1222a1601488 ("nl80211: Fix possible Spectre-v1 for CQM RSSI thresholds") Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Masashi Honma masashi.honma@gmail.com Link: https://lore.kernel.org/r/20190908005653.17433-1-masashi.honma@gmail.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/wireless/nl80211.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -9753,9 +9753,11 @@ static int cfg80211_cqm_rssi_update(stru hyst = wdev->cqm_config->rssi_hyst; n = wdev->cqm_config->n_rssi_thresholds;
- for (i = 0; i < n; i++) + for (i = 0; i < n; i++) { + i = array_index_nospec(i, n); if (last < wdev->cqm_config->rssi_thresholds[i]) break; + }
low_index = i - 1; if (low_index >= 0) {